Pinless piston



Sept. 16, 1,930. A. BDE sALARDl 1,775,892

'PINLESS PISTON Filed March 7, 1929 i Y. 2.o

l Patented Sept.l 16, 171930 ALBERT' B EnNHARnnE sALAnDr, or' roar ARTHUR., frans PINLESS PISTON Application med umh 7,

Thisinvention relates to piston construc-A tion for internal combustion engines, steam engines, pumps, compressors and the like, and

has forits main object to provide a combined 5 unitary vpiston and connecting rod construction'whichwill be extremely simple, safe and eificient in operation and which will do away with the-,present connecting rod pins thereb greatly simplifying the mechanism to whic the present connecting rod and piston con-, struction where the greatest wear and most frequent breakdowns occur.

Incidentally mywinvention also aims and elimination of the lateral pressures resulting from the reactions which now arise in the above'mentioned machine elements.

- As it is well known the piston andconnecting rod mechanisms where the two elements are connected by a pin and are used in combination with a crank shaft to transform a reciprocal movement into. a rotatingone, or vice versa, haveat present a conspicuously weak point being represented b which is'subject to great stress an intensive friction requirin frequent and expensive repair. Another orce acting on the piston. will have a different direction from that of thecenter line of the connecting rod, which latter is the direction of the transmission of l the power, thereby causing transversecomponents in the forces acting, which again leads to the well known harmful intensive friction between the pistoni andthe cylinder wall. This and other disadvantages will be eliminated byl my in;-

vention, as will be apparent as the specifica tion of the same proceeds.

In the drawings forming a part of this specification and being appended'hereto:

Fig. lis a fragmentary sectional view of a piston 'and connecting rod constructed according to one y,embodiment of my invention, with portions of the cylinder and crank shaft also being'shown.

Fig. 2 .is another fragmentary sectional, view of the preferred mo 'fication of my pisit relates and doing away. with such parts of will lead yto a great reduction or almost total' thereof various parts thereo the pin' isadvantage of the present i piston connecting rod construction is that the .temperatures created. The s herical 1929. serial m3443157.

Figs. 5 and 6 are elevational views-'of 60 spherical pistons Iwith associated sliding sleeves, parts of said sleeves being in section said figures showin further modifications of my inventive thong t.

Referring now to the drawings,more close- 65 ly, by characters of reference, the numeral l; indicates a section of a cylinder in which my plston 2 is operating. lThe piston 2 is for-med mainly of a portion of a hollow sphere. and it l will be obvlous that durin will always be in contact with the cylinder wall and will make a closure between the two parts of the cylinder, the tightness of said -closure being dependent on the workmanshi dimensions of the cylinder an the s herical piston head. As a rule the outside of the sphere of the piston will be slightly smaller than the inside diameter of the cylinder in order to. allow for the necessar heat 86 expansion by the materials used and y Athe iston 2 and the inner cylinder wa ls will a wa'ys have a close line of contact, which willsubstantially be a meridian circle of the sphere, 85

and which, with due lubrication will offer a sufficient resistance against the leakage of combustion gases, steam or air, or any other uid medium under pressure.

The piston 2may have a fiat bottom wall 9 .from which projects connecting rod 3 which may be an integral part of the piston head construction 2, as shown in Fig. 1, but it will be understood that it may be made as a sepa- 95 rate piece o f mechanism and then secured and rigidly fastened to the spherical head. Rod 3 is rotatably secured at itsother end 4 on a usual crank shaft 6, said end 4 with a lower bearing shell 5 and with the usual bolts form- 100 the Voperation and relative 72 'ameter ing the well known connecting rod bearing for the crank shaft pin. f

The flat bottom of the piston sphere 2 may have larger bores 7 provided around the end of the rod 3 for the purpose of admitting a lubricant preferably thrown up by the revolving crank into the inner space of theV hollow piston sphere and said hollow sphere may also have smaller bores or holes 8 adapted to distribute the lubricating material on the cylinder wall. One extreme position of the piston with its connecting rod is shown by the dottedlines and in such position the center line of the connecting rod will be tangential to the circular arrow in the lower portion of Fig. 1,. indicating the line of rotation of the center of the crank shaft pin and in such position the center lines of the cylinder and of the connecting rod will form the angle a, -being the greatest angle between aid two li'nes.

In ig. 2 there is shown a fragment of a cylinder 10 with a spherical piston 9 and a portion of'its integral connecting ro'd 12. The top and bottom' ends of the hollow spherical piston 9 are cut away and open in this construction and the connecting rod 12 is integral or secured to a central dividing wall 11-in said hollow sphere. The plane of the dividing wall 11 is perpendicular to the center line of the connecting rod 12 so that the pressure of the working medium in the cylinder 10 will exert forces perpendicular to the dividing wall 11 and always in the direction of the center line of the connecting rod 12 as indicated by the small arrows towards said wall 11. The resultant of these yforces is indicated by the letter P and by the arrow to which it points', while the reaction inthe connecting rod caused by the same is indicated by the letter R, the two being inthe same lines, but in opposite directions, while their transverse components M and N pointing towards and being perpendicular with the cylinder wall always being equal and also opposite in direction, so that one such transverse component will entirely counterbalance the other one. It is obvious therefore that there will be no force or tendency to press the piston on the cylinder walls in any direction and therefore there will practically be no friction and wear and tear between the cylinder walls and the spherical piston head.

The herein described condition is a theoretical and ideal one, based on thel assumption that the total pressure of the working fluid' will act on the dividing wall 11 only, but due to the thickness of the wall of the spherical piston the inside surface of the dividing wall 11 is somewhat smaller than the i area of the bore of the cylinder and the between the spherical `piston and the cylin` ment shown in Fig. 2 is illustrated. Piston i 14 is similarly constructed to the one shown in Fig. 2 having a dividing wall 15 and the connecting rod 16 secured to or integral therewith. The outside diameter of the Spherical piston 14 in this modification, however, is considerably smaller than the inside diameter of the cylinder 13 and a sleeve 20 is interposed between the two, the outside cylindrical surface of said sleeve slidingly fitting into lthe cylinder, while the spherical piston 14 ts into the inside spherical surface of the sleeve 20.

The operation of this as well as theA earlier two embodiments of my invention will be obvious by inspecting the drawings. In this last embodiment illustrated in Fig. 3 the working iiuid will exert a pressure on the dividing wall 15 of the piston as well as on the endsurfaces of the sleeve 20 and thev two will move together, the spherical piston describing an oscillatingmotion .within the sleeve 20. y

An oil duct 17 may be provided in the connecting rod 16 leading to transverse ducts 18 and 19 in the dividing wall 15 distributing the lubricant in the groove on the'outside spherical sliding surface. The location and arrangement of these grooves may be made in such a manner that they will never be exposed to the high pressure working medium. Sleeve 20 may be made in one piece, forged or pressed over the spherical piston by suitable shop operations or it may be split and resilient like the usual piston ring having a tendency to expand. Similarly as in the case of the construction of Fig. 2, lif the side thickness of the piston 14 and of the sleeve 20 is reduced the transverse component of the working forces and the fric- `tion on the cylinder wall caused by them may be kept verysmall.

lOl)

In Fig.4 I show a still further modified form of my piston in section, with the surrounding portions of a sleeve in which it is adapted to operate. The piston has a spherical outside surface 22 and a flat outside surface 21 exposed to the working pressure. 23 indicates the connecting rod and 24 are holes or bores in the lower part of the piston to reduce its weight. The flat surface 21 is perpendicular to the center line of the connecting rod 23 in order to insure that the working pressure is directly transmitted to the conthe sphere 22 and may have grooves l26 in its outside surface, while grooves 27 may be provided on the inside surface of said sleeve so that lubricating materials may be interposed A connecting rod 15 is secured thereto.

between the cylinder walls and the sleeve on the one side and between the sleeve and the spherical piston on the other side. The lgroove may again be located in such amanner that it will not be exposed to the pressure of the working medium during the usual operating movements of the parts. The position of the piston and of the connecting rod when they form the greatest outward angle a with the center line of the cylinder is indicated by the dotted lines. The piston head also may have grooves on its outside surface for the distribution of the lubricating materials and holes leading from its hollow inside to said grooves, these vgrooves and holes not beingl shown in the figure.

Fig. 5 is an elevational view of a piston and its sleeve Vconstructed on similar principles to those of the mechanism in Fig. 3. Spherical piston 14 is surrounded by a sleeve 29 and a The sleeve 29 is split and'formed with cooperating grooves and tongues 30, while oil distributing grooves 28 may be provided in its outside surface being connected by throughgoing holes with oil grooves on the inside surface of the sleeve. Sleeve 29 may be made with a tendency for radial expansion so that it will be adapted to fill the space between the piston and the cylinder, acting in the manner of a series of effective piston rings.

hollow body, open 'at both ends, the outside surface of said hollow body being the central portion of a sphere, a partition wall inside of said hollow body going through the center of said sphere, said partition wall forming a circular working surface to receive the pressure of the working medium, a connecting rod rigidly attached to said partition wall, the centerline of said connecting rod being perpendicular tov said circular working surface and going through its center, and oil ducts in said connecting rod and partition wall leading to the outside surface of the hollow body.

2. For use with a machine having a working cylinder, a pinless piston of claim 1, a sleeve encircling the hollow piston body, the inside surface of said sleeve being a spherical zone slidingly fitting around the outside surface of the hollow piston body and the outside surface of said sleeve being cylindrical, slidingly fitting into said working cylinder,

, said sleeve having oil distributing grooves on its outside and inside surfaces, connected by othroughgoing holes.

Signed at Port Arthur, inthe county of Jefferson and State of Texas, this fourth day of March, A. D. 1929. ALBERT BERNHARD DE SALARDI.

'lou

Fig.'6 is a view similar to that of Fig. 5

and shows a somewhat similar construction wherein piston 31 is similarly constructed to those of Figs. 3 and 5 and is surrounded by a sleeve 33 which may have circumferential grooves and usual piston rings 34 therein.

All the piston constructions shown in Figs. 1 to 6 may be manufactured easily and conveniently from drop forged or punched metal parts, welded or otherwise rigidly fastenedv together and their sliding surfaces may be highly finished and polished.

It is understood that changes and variations may be made in the various parts of my invention and I hereby reserve all my rights to such modications as are within the spirit of the invention and the scope of the appended claims.

One such change maybe made by providing several surfaces instead of the surface 1l which'is perpendicular tothe center line of the connecting rod 12, said surfaces being arranged in such a manner that the resultant of the pressure of the working medium on these surfaces will act in the center line of said rod. 

